Slide rule accessory



May 3, 1949.

J. G- ADILETTA SLIDE RULE' ACCESSORY Filed Aug. 28, 1945 2, H I 1 am -A Patented May 3, 1949 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to slide rules of the type having scales upon its opposite faces, and provided with a runner adapted to be utilized with either of the faces. When working with this slide rule it is usually held in one hand, while its sliding bar and runner are operated with the other hand. Though it is often deemed desirable to work with one face of this slide rule, while its opposite side rests upon a table or drawing board, such recourse cannot at present be resorted to because it would injure the opposite face and interfere with the operation of the runner.

The principal object of the invention is to provide an accessory for the above type of slide rule, wherewith it may be interchangeably converted from its normal utilization while held in the hand to a, condition permitting its operation when placed upon a table or drafting board, such mode of operation being conducive to utilizing the slide rule with enhanced accuracy and speed.

Other objects and advantages will hereinafter appear.

In the accompanying drawings,

Fig. 1 is a perspective view of a double-faced slide rule, showing it as it appears when equipped with the accessories of this invention.

Fig. 2 is an end elevation of the slide rule accessory constituting the invention.

Fig. 3 is a plan view of the accessory shown in Fig. 2.

Fig. 4 is a side elevation of the accessory shown in Fig. 2.

Fig. 5 is a top view of a slide rule, showing it with the right end thereof in its normal appearance, and its left end as it appears when having the accessory of the invention mounted thereon.

Fig. 6 is an end elevational view of the slide rule and the accessory mounted thereon, as they appear when placed for operation upon a table.

The slide rule I, Fig. 5, comprises a pair of scale-bearing rails 2, secured to each other by fittings 3, a sliding bar 4, and a runner 5. The accessory 6, Figs. 2, 3, 4, consists of supporting fixtures 'l, 8, secured by means of rivets 9 to a pair of springy plates [0, which are normally curved, as appearing in Fig. 4, to maintain the fixtures l, 8 parallel to each other, but which may be flexed backwardly, as shown by the dash and dot lines, to spread said fixtures angularly to each other. Each of the supports I, 8 is hollow as shown in Fig. 4, providing a fiat base ll, Fig. 2, and is configurated as shown in Fig. 3 to encompass the fitting 3 of the slide rule. The fixture I is provided with projecting lips [2. The accessory 6 is readily and conveniently mounted over the end of slide rule I, in the position illustrated in Figs. 1, 5, by merely spreading apart its fixtures 1, 8 and permitting them to spring back over the end of the rule, in encompassment with the fitting 3. In this position, the edges l3 of the support bear against the lateral edges 3a of fitting 3 to maintain the accessory against displacement longitudinally of the slide rule, while its lips l2 project over the rails 2 to maintain the accessory laterally. The accessory 6 is as conveniently demounted and removed from the slide rule, by spreading apart its fixtures l, 8 and slipping it off the rule.

When the slide rule is thus equipped with a pair of accessories 6 at its ends, as illustrated in Fig. 1, it may be placed upon a table Hi as shown in Fig. 6, with the faces ll of the fixtures l or 8 of both accessories resting upon the table and thereby elevatingly supporting the slide rule I over the surface of the table, to permit manipulation of its sliding bar 4 and runner 5. On removal of the accessories 6, the slide rule is restored to normal utilization by being held with the hand.

Variations may be restored to within the scope of the invention.

Having thus described my invention, I claim:

1. An accessory for maintaining a double-faced slide rule in elevated state upon a table for manipulation of the slide rule in said state, comprising a pair of members each having the combination of a. lower fixture for elevatingly supporting the slide rule to present one face thereof in an operative condition, an upper fixture for similarly supporting the slide rule for similarly presenting its opposite face, a spring joining said fixtures, said spring drawing said fixtures toward each other for grippingly holding the slide rule and for removal of the member from the slide rule, and said members being mountable upon and demountable from the marginal end portions of the slide rule.

2. An accessory for maintaining a double-faced slide rule in elevated state upon a table for manipulation of the slide rule in said state, compris- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,181,672 Keuffel May 2, 1916 2,205,524 Garnis June 25, 1940 

